This is what the menu looks like most of the time, though not always blue (sometimes it's completely black). It wasn't like this for a long time, but the past few days it's done this. I am using Optifine; could that be the cause? It doesn't happen if I open it while in third person mode.
These are the mods I have installed:

that happens to me too, and I'm on 1.12.2 also, by the way, if you use mrcrayfish's mods, get rid of them, or atleast get them off of your mod files, they cause your ears (i think only ears) to float above your head when looking up or down, i think it also happens in 1.12.2 as the same problem when making your player model look up or down in your inventory, me and the tails mod (this one, that this issue for a mod issue/problem is about) owner (aka Kihira) found out when the owner said that it's Obfuscate because it messes with your player model and that mod is the core to what makes your mrcrayfish mods work.

I'm not entirely sure what causes this issue, usually its another mod but can't be sure.

I'm overhauling the UI in the next version of the mod so this should hopefully fix it then.

This bug also happened to me but only with the chocapic shader.

also, with some java arguments, the player's 3D model is not refreshed, which means you need to leave the editor to see the changes.

-Xmx3G -Xms3G -Xmn768m -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+UseNUMA -XX:+CMSParallelRemarkEnabled -XX:MaxTenuringThreshold=15 -XX:MaxGCPauseMillis=30 -XX:GCPauseIntervalMillis=150 -XX:+UseAdaptiveGCBoundary -XX:-UseGCOverheadLimit -XX:+UseBiasedLocking -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=15 -Dfml.ignorePatchDiscrepancies=true -Dfml.ignoreInvalidMinecraftCertificates=true -XX:+UseFastAccessorMethods -XX:+UseCompressedOops -XX:+OptimizeStringConcat -XX:+AggressiveOpts -XX:ReservedCodeCacheSize=2048m -XX:+UseCodeCacheFlushing -XX:SoftRefLRUPolicyMSPerMB=10000 -XX:ParallelGCThreads=10

I also have the probleme and from what i have seen, it is link with the light level or your position in the map: if you open the menu during the day under the sun light or near torches, you have no probleme. If you open the menu in a dark location (or somewhere with a low light level), it will be blue or black depending of the light level.